314 TRANSFORMATIONS OF INSECTS. 
solitary bees. Another species selects the hive bee, and lays its 
eggs in the cells with the larve of the bees. The larve of the 
beetles, when they have destroyed those of the bees in one part 
of the hive, search out the others, and proceed from cell to cell 
devouring the inhabitants of each. 
In the engraving on page 313 the nests of the bee are seen 
in section, and the larva of the beetle is drawn between two adults. 
Another species (Clerus formicarius) is a little red insect, 
which is rather common, and its larve live under the bark of 
old trees, where they chase and devour many wood-eating in- 
sects, especially larvae. Others, belonging to the genus Vecrodza, 
feed, both in the perfect and larval state, upon carrion and dead 
animal matter, such as dried skins and old bones. They are 
very common in houses, and one species frequents prisons and 
other gloomy places. Some of the larve of the genus Axobium 
live in old wood, which they eat, and they undergo their meta- 
morphosis in a small cell, which they form within planks and 
beams in old furniture, and when they become beetles they eat their 
way out by drilling small round holes, which every one has seen 
in old houses. The beetles are nocturnal in their habits, and 
call each other by striking their mandibles against wood, and 
they answer each other in the same manner. The blow produces 
a little tick, and it is repeated at intervals. The beetle being in- 
visible, superstitious people have a nervous dread of it, and many 
old women, especially nurses, call it the death tick, and prophesy 
a fatal issue of the complaints of the sufferers they are watching 
if the beetle calls its love in this very disagreeable manner. 
Elm trees are very often noticed to be scored beneath the 
bark by radiating lines, which are arranged in a very regular 
manner. This is the work of a most destructive beetle, which 
is called Scolytus destructor. It is worthy of its name, for many 
large trees and whole forests finally succumb to its attacks. 
They have small and projecting heads, club-shaped antenne, 
and very strong mandibles. In the adult form they nibble the 
bark of trees, and suck the sap, and the females lay their eggs 
on the. trees the sap of which does not circulate very actively. 
The female penetrates underneath the bark, and screws herself in 
between it and the woody tissue. She makes a. gallery, into 
